Relay station and radio communication system

ABSTRACT

In order to achieve effective utilization of radio communication resource, there is provided a relay station, for relaying a signal to be transferred between a radio base station and a radio terminal, which includes a storage section adapted to store communication controlling information for communication control with the radio terminal, a base station side signal reception section adapted to receive, from the radio base station, scheduling information in communication between the radio base station and the radio terminal through the relay station, a complementation section adapted to complement contents of the scheduling information received by the base station side signal reception section in accordance with the communication controlling information stored in the storage section, and a terminal side signal transmission section adapted to transmit the scheduling information whose contents are complemented by the complementation section to the radio terminal.

CROSS REFERENCE

This application is a divisional of U.S. patent application Ser. No.12/429,340, filed Apr. 24, 2009, which is a continuation of PCTApplication PCT/JP2006/321299 filed on Oct. 25, 2006, the entirecontents of both of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a radio base station, a relay station,a radio communication system and a radio communication method whichutilize radio communication, and particularly relates to a techniquesuitable for use with, for example, a system prescribed by the IEEE802.16.

BACKGROUND ART

At present, a radio communication system wherein communication iscarried out through a radio communication path as represented by asystem of WCDMA, CDMA2000 or the like is used popularly in the world. Insuch a radio communication system as just described, a radio basestation (BS; Base Station) is provided in a service area such that aradio terminal carries out communication with a different communicationapparatus (communication terminal) through

the radio base station.

FIG. 18 shows a connection scheme of the P-MP (Point to Multipoint) typewherein a radio base station 101 connects to a plurality of radioterminals (MS; Mobile Stations) 102 in a cover area (cell) 100 thereof.In the IEEE (The Institute of Electrical and Electronics Engineers,Inc.) 802.16 which is the standards of high-speed radio datacommunication, such a P-MP scheme as shown in FIG. 18 is prescribed as aform of communication. Further, in the IEEE 802.16 WG, principally twokinds of specifications including the 802.16d specifications(802.16-2004) for point-to-point communication applications and the802.16e specifications (802.16e-2005) for mobile communicationapplications are prescribed.

In such a P-MP type connection scheme as shown in FIG. 18, since theservice area is limited to the inside of the cell 100 of the radio basestation 101 and the radio environment is not good on the boundary (celledge) of the cell 100, high-speed communication is in most casesdifficult.

In order to solve this problem, the IEEE 802.16 WG establishes a taskgroup 802.16j for developing a specification of a relay system where arelay station (RS; Relay Station) carries out relay between a radio basestation and a radio terminal, and the working of the task group isproceeding at present.

It is to be noted that matters relating to the IEEE 802.16 describedabove are disclosed, for example, in Non-Patent Documents 1 to 3 listedhereinbelow.

Further, a technique is disclosed in Patent Document 1 listedhereinbelow wherein, in a relay system through a relay station, a radiobase station decides scheduling in communication between a relay stationand a radio terminal, and the relay station receives schedulinginformation between the relay station and the radio terminal from theradio base station and executes communication control between the relaystation and the radio terminal based on the scheduling information. Atthis time, since the scheduling process is executed in a concentratedmanner by the radio base station, it is sufficient for the relay stationto have an easy implementation.

In the technique disclosed in Patent Document 1, where the overallscheduling in communication between the relay station and the radioterminal is carried out by the radio base station, it becomes necessaryfor the relay station to relay a signal and data received from the radioterminal to the radio station without changing the contents of thesignal and the data. This is because the information of the radioterminal received by the relay station is required by the radio basestation in order that the radio base station carries out, in place ofthe relay station, scheduling between the relay station and the radioterminal.

-   Non-Patent Document 1: IEEE Std802.16-2004-   Non-Patent Document 2: IEEE Std802.16e-2005-   Non-Patent Document 3: 2006 Comprehensive Meeting of The Japan    Society of Information and Communication Research B-5-140 “Effects    of the multiple MAP (map) in the IEEE 802.16 relay system”-   Patent Document 1: Japanese Patent Laid-Open No. 2006-74325

DISCLOSURE OF THE INVENTION Subject to Be Solved by the Invention

According to the background art described above, a radio terminal cancarry out radio communication with a radio base station directly orthrough a relay station.

However, since information of the radio terminal received by the relaystation is required by the radio base station in order for the radiobase station to carry out scheduling between the relay station and theradio terminal in place of the relay station, consumption of a bandwhich is a radio communication resource increases.

Therefore, it is one of objects of the present invention to achieveeffective utilization of a radio communication resource.

It is to be noted that, in addition to the object described above, alsoit shall be understood as another one of objects of the presentinvention to achieve such effects as are provided by the constitutionsindicated by the best mode for carrying out the present inventionhereinafter described but are not achieved by the conventionaltechniques.

Means for Solving the Subject

(1) In order to attain the object described above, according to anaspect of the present invention, there is provided a relay station whichrelays a signal to be transferred between a radio base station and aradio terminal, the relay station including a storage section adapted tostore communication controlling information for communication controlwith the radio terminal, a base station side signal reception sectionadapted to receive, from the radio base station, scheduling informationin communication between the relay station and the radio terminal, acomplementation section adapted to complement contents of the schedulinginformation received by the base station side signal reception sectionin accordance with the communication controlling information stored inthe storage section, and a terminal side signal transmission sectionadapted to transmit the scheduling information whose contents arecomplemented by the complementation section to the radio terminal.

(2) Preferably, the relay station further includes a terminal sidesignal reception section adapted to receive a signal and a message fromthe radio terminal and store information of the received signal andmessage into the storage section, an intensive collection sectionadapted to intensively collect the information of the signal and messagefrom the radio terminal, and a base station side signal transmissionsection adapted to transmit the information intensively collected by theintensive collection section to the radio base station in order toproduce the scheduling information.

(3) In this instance, preferably the terminal side signal receptionsection receives signals and messages from a plurality of radioterminals and stores information of the received signals and messages asthe communication controlling information into the storage section; theintensive collection section intensively collects the information of thesignals and messages from the plural radio terminals into one piece ofinformation; and the complementation section complements the contents ofthe scheduling information received by the base station side signalreception section in an associated relationship with communicationcontrolling information of each of the plural radio terminals inaccordance with the communication controlling information stored in thestorage section.

(4) Or, the relay station may be configured such that the terminal sidesignal reception section receives band request signals from the radioterminals and stores, as the communication controlling information, kindinformation of the band request signals and position information of theband request signals in a terminal transmission region as information ofthe received band request signals into the storage section, theintensive collection section intensively collects the information of theband request signals from the radio terminals, and the complementationsection complements, regarding the scheduling information received bythe reception section, the kind information of the band request signalsand the position information of the band request signals in the terminaltransmission region stored in the storage section.

(5) Or else, the relay station may be configured such that the terminalside signal reception section receives power/timing adjustment signalsfrom the radio terminals and produces power/timing adjustmentinformation for the corresponding radio terminals from the receivedpower/timing adjustment signals and then stores kind information of thepower/timing adjustment signals and position information in a terminaltransmission region as the communication controlling information intothe storage section together with the produced power/timing adjustmentinformation, the intensive collection section collects information ofthe power/timing adjustment signals from a plurality of the radioterminals, the complementation section complements, regarding thescheduling information and messages received by the reception section,the kind information of the power/timing adjustment signals and theposition information of the power/timing adjustment signals in theterminal transmission region stored in the storage section, and theterminal side signal transmission section transmits the power/timingadjustment information corresponding to the power/timing adjustmentsignals stored in the storage section to the radio terminals togetherwith the scheduling information whose contents are complemented by thecomplementation section.

(6) Further, according to another aspect of the present invention, thereis provided a relay station which relays a signal to be transferredbetween a radio base station and a radio terminal, the relay stationincluding a terminal side reception section adapted to receiveinformation of a signal and a message transmitted from the radioterminal, a decision section adapted to decide based on the informationreceived by the terminal side reception section whether or not anotification of the information relating to the signal and the messagereceived from the radio terminal is to be issued to the radio basestation, and a notification section adapted to issue the notification ofthe relating information to the radio base station when it is decided bythe decision section that the notification of the information relatingto the signal and message received from the radio terminal is to beissued to the radio base station.

(7) Preferably, the relay station of (6) described above may beconfigured such that the terminal side reception section receivesinformation of a signal and a message relating to a radio channel statebetween the relay station and the radio terminal transmitted from theradio terminal; the decision section decides, based on the informationrelating to the radio channel state between the relay station and theradio terminal received by the reception section, that a notification ofthe relating information is to be issued to the radio base station whena radio communication method used between the relay station and theradio terminal need to be changed; and the notification section issues,when it is decided by the decision section that the radio communicationmethod need to be changed, a notification of at least one of the radiochannel information and the radio communication method between the relaystation and the radio terminal as a notification of the relatinginformation to the radio base station.

(8) According to a further aspect of the present invention, there isprovided a radio base station for transmitting and receiving a signal toand from a radio terminal through the relay station in (2), the radiobase station comprising a reception section adapted to receiveinformation from the base station side signal transmission section ofthe relay station, a scheduling information production section adaptedto produce the scheduling information except for information to becomplemented by the complementation section of the relay station basedon the information received by the reception section, and a transmissionsection adapted to transmit the scheduling information produced by thescheduling information production section to the relay station.

(9) According to a still further aspect of the present invention, thereis provided a radio base station for transmitting and receiving a signalto and from radio terminals through the relay station in (4), the radiobase station comprising a reception section adapted to receiveinformation from the base station side signal transmission section ofthe relay station, a scheduling information production section adaptedto carry out band allocation by the number equal to the number of bandrequest signals intensively collected in the information received by thereception section and produce the scheduling information based on theinformation received by the reception section, and a transmissionsection adapted to transmit the scheduling information produced by thescheduling information production section to the relay station.

(10) According to a yet further aspect of the present invention, thereis provided a radio base station for transmitting and receiving a signalto and from a radio terminal through the relay station in (5), the radiobase station including a reception section adapted to receiveinformation from the base station side signal transmission section ofthe relay station, a scheduling information production section adaptedto produce the scheduling information for which band allocation by thenumber equal to the number of power/timing adjustment signalsintensively collected in the received information is carried out basedon the information received by the reception section, and a transmissionsection adapted to transmit the scheduling information produced by thescheduling information production section to the relay station.

(11) According to a yet aspect of the present of the present invention,there is provided a radio communication system comprising radioterminals, a radio base station for transmitting and receiving signalsto and from the radio terminals, and a relay station for relaying asignal to be transferred between the radio terminals and the radio basestation, the relay station including a terminal side signal receptionsection adapted to receive signals and messages from the radio terminal,a storage section adapted to store information of the signals andmessages received by the terminal side reception section ascommunication controlling information for communication control betweenthe radio terminals and the relay station, an intensive collectionsection adapted to intensively collect the information of the signalsand the messages from the radio terminals, and a base station sidetransmission section adapted to transmit the information intensivelycollected by the intensive collection section to the radio base station,the radio base station comprising a reception section adapted to receiveinformation from the base station side signal transmission section, ascheduling information production section adapted to produce schedulinginformation in communication between the relay station and the radioterminals except for information to be complemented by thecomplementation section of the relay station based on the informationreceived by the reception section of the relay station, and atransmission section adapted to transmit the scheduling informationproduced by the scheduling information production section to the relaystation, the relay station further including a base station side signalreception section adapted to receive the scheduling information from theradio base station, a complementation section adapted to complementcontents of the scheduling information received by the base station sidesignal reception section in accordance with the communicationcontrolling information stored in the storage section, and a terminalside signal transmission section adapted to transmit the schedulinginformation whose contents are complemented by the complementationsection to the radio terminals.

(12) According to a yet further aspect of the present invention, thereis provided a radio communication system comprising a radio terminal, aradio base station for transmitting and receiving a signal to and fromthe radio terminal, and a relay station for relaying a signaltransferred between the radio terminal and the radio base station, therelay station including a radio channel state reception section adaptedto receive information of a signal and a message relating to a radiochannel state between the relay station and the radio terminal from theradio terminal, a decision section adapted to decide based on theinformation received by the channel state reception section whether ornot a radio communication method used between the relay station and theradio terminal needs to be changed, and a notification section adaptedto issue, when it is decided by the decision section that the radiocommunication method needs to be changed, a notification of at least oneof radio channel information and the radio communication method betweenthe relay station and the radio terminal as relating information to theradio base station, the radio base station comprising a schedulinginformation production section adapted to change a radio communicationmethod to be used between the radio base station and the radio terminalthrough the relay station and produce scheduling information incommunication wherein the radio communication method is changed based onthe relating information issued from the notification section, and atransmission section adapted to transmit the scheduling informationproduced by the scheduling information production section to the relaystation.

(13) It is to be noted that, in the radio communication system of (12)described above, the radio communication method which is a target of thechange may include a modulation method, a coding method and a codingratio as elements thereof.

(14) Further, according to a yet aspect of the present of the presentinvention, there is provided a radio communication method by a pluralityof radio terminals, a radio base station for transmitting and receivingsignals to and from the radio terminals and a relay station for relayinga signal to be transferred between the radio terminals and the radiobase station, the method including, in the relay station, receivingsignals and messages from the radio terminals, storing information ofthe received signals and messages as communication controllinginformation for communication control between the radio terminals andthe relay station, intensively collecting the information of the signalsand messages from the radio terminals, and transmitting the intensivelycollected information to the radio base station, in the radio basestation, receiving the intensively collected information from the relaystation, producing scheduling information for communication between therelay station and the individual radio terminals based on the receivedintensively collected information, and transmitting the schedulinginformation to the relay station, and, in the relay station, receivingthe scheduling information transmitted from the radio base station,complementing contents of the received scheduling information inaccordance with the stored communication controlling information, andtransmitting the scheduling information whose contents are complementedto the radio terminals.

(15) According to a yet aspect of the present invention, there isprovided a relay station interposed between a radio base station andradio terminals for carrying out a relay process, the relay stationincluding a storage section adapted to store information obtained byreception of signals from the radio terminals, a notification sectionadapted to issue to the radio base station a notification of securing ofa transmission region in an upward direction based on the receivedsignal, a reception section adapted to receive transmission regioninformation in the upward direction in the relay station secured by theradio base station in accordance with the notification, and atransmission section adapted to add contents to the transmission regioninformation based on the information stored in the storage section andtransmit the transmission region information to which the contents areadded in a downward direction.

Effect of the Invention

In this manner, with the present invention, since scheduling informationof the radio terminal can be complemented by the relay station, there isan advantage that effective utilization of radio communication resourcecan be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating an example of a configuration of a radiocommunication system to which embodiments of the present invention areapplied.

FIG. 2 is a view illustrating an example of a radio frame format towhich the embodiments are applied.

FIG. 3 is a view illustrating a signal sequence in a first embodiment ofthe present invention.

FIG. 4 is a view illustrating a signal sequence as a comparative exampleto the signal sequence of the first embodiment.

FIG. 5 is a block diagram showing a relay station in the firstembodiment.

FIG. 6 is a view illustrating information to be stored by a storagesection of the relay station in the first embodiment.

FIG. 7 is a view illustrating an example of a configuration of acontrolling message to be produced by a notification section of therelay station in the first embodiment.

FIG. 8 is a block diagram illustrating a radio base station in the firstembodiment.

FIG. 9 is a view illustrating a signal sequence in a second embodimentof the present invention.

FIG. 10 is a block diagram illustrating a relay station in the secondembodiment.

FIG. 11 is a view illustrating information to be stored in a storagesection of the relay station in the second embodiment.

FIG. 12 is a view illustrating an example of a configuration of acontrolling message to be produced by a notification section of therelay station in the second embodiment.

FIG. 13 is a block diagram illustrating a radio base station in thesecond embodiment.

FIG. 14 is a view illustrating a signal sequence in the third embodimentof the present invention.

FIG. 15 is a block diagram illustrating a relay station of a thirdembodiment.

FIG. 16 is a view illustrating information to be stored in a storagesection of the relay station in the third embodiment.

FIG. 17 is a view illustrating an example of a configuration of acontrolling message to be produced by a notification section of therelay station in the third embodiment.

FIG. 18 is a view illustrating a radio communication system.

DESCRIPTION OF REFERENCE CHARACTERS

-   -   1 radio communication system    -   2, 2′, 2A to 2C radio base station    -   2 a cover area    -   3, 3′, 3A to 3C relay station    -   4-1, 4-2, 4-21 to 4-23 radio terminal    -   100 cover area    -   101 radio base station    -   102 radio terminal    -   201, 211 reception section    -   202, 212 controlling message extraction section    -   203, 213 scheduling section    -   204, 214 NW interface section    -   205, 215 buffer section    -   206, 216 transmission section    -   301, 311, 321 reception section    -   302, 312, 322 Code reception section    -   303, 313, 323 storage section    -   304, 314 intensive collection section    -   305, 315, 325 notification section    -   306, 316, 326 transmission section    -   307 UL MAP (map) extraction section    -   308, 318 relay section    -   317 DL MAP (map) extraction section    -   324 decision section

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, embodiments of the present invention are describedwith reference to the drawings.

[a] Description of an Example of the Configuration of the RadioCommunication System to which the Embodiments are Applied

FIG. 1 is a view illustrating an example of a configuration of a radiocommunication system to which the embodiments are applied. A radiocommunication system 1 illustrated in FIG. 1 includes a radio basestation (BS) 2, a relay station (relay station; RS) 3, and a pluralityof (here, two) radio terminals (MS#1, MS#2) 4-1 and 4-2. It is to benoted that, where the radio terminals 4-1 and 4-2 are not distinguishedfrom each other in the following description, the radio terminal isreferred to simply as radio terminal 4.

Then, the radio terminal 4-1 existing in a cover area 2 a of the radiobase station 2 can carry out transfer (communication) of a radio signalwith the radio base station 2 (BS-MS link), and the radio terminal 4-2outside the cover area 2 a of the radio base station 2 can carry outradio communication with the radio base station 2 through the relaystation 3 (BS-RS link and RS-MS link). It is to be noted that, as theradio terminal 4, not only an MS suitable for movement but also a radioapparatus suitable for utilization in a stationary state can be used.

A radio frame format for radio communication among the radio basestation 2, relay station 3 and radio terminals 4-1 and 4-2 describedabove is illustrated as an example of a radio frame format to which thepresent embodiment is applied in FIG. 2. It is to be noted that, while aradio frame format ready for the IEEE Std802.16d,e is taken as anexample here, the present invention is not limited to this.

In FIG. 2, reference characters Tx and Rx signify transmission andreception, respectively. Accordingly, the BS 2 transmits a DL/UL MAP(map), MMR bursts #1 and #2 and a downward burst T4-1 in order whileusing a preamble (P) as the top of the frame. It is to be noted that theMMR burst #1 is transmission data from the radio base station 2 to arelay station not shown in FIG. 1; the MMR burst #2 is transmission datato the relay station 3 shown in FIG. 1; and the downward burst 4-1 istransmission data to the radio terminal 41 in FIG. 1.

The preamble (P) is a synchronizing signal to be transmitted to theinside of the area of the radio base station 2 to make it possible forthe relay station 3 to be synchronized with the radio base station 2 andis transmitted as a predetermined known pattern in a fixed period. It isto be noted that, in FIG. 2, if an Up Link Sub-frame (up link sub-frame)ends, then transmission of a Down Link Sub-frame (down link sub-frame)is started again in order from the preamble.

The radio terminal 4 can store plural kinds of patterns of the preamblein advance such that a pattern whose reception quality (for example,reception level) is highest from among the patterns is selected as thatof the radio base station 2 which is a communication destination.

Where, for example, OFDMA (Orthogonal Frequency Division MultiplexingAccess) is utilized as a radio method, while the radio base station 2allocates the transmission data to different sub carriers and the pluralsub carriers are used to carry out transmission, also the preamble canbe al located to the sub carriers with a predetermined pattern andtransmitted. The radio terminal 4 can receive a combination ofpredetermined sub carriers to carry out matching with the known preamblesignal so as to establish synchronism with the radio base station 2which transmits the best preamble.

The DL/UL MAP (map) is transmitted subsequently to the transmission ofthe preamble of the Down Link Sub-frame (down link sub frame) and iscontrolling data for controlling transmission and reception operation oftransmission and reception timings, transmission and reception channels,a radio communication method (modulation method, coding method, codingrate or the like) and is so forth with regard to the relay station 3 andthe radio terminal 4-1. The MAP (map) data includes DL MAP (map) dataand UL MAP (map) data, and the DL MAP (map) data defines a structure ofa downward sub frame and the UL MAP (map) data defines a structure of anupward sub frame.

The DL MAP (map) data includes data for the notification of atransmission timing and a transmission channel (a reception timing and areception channel to the reception side), a radio communication methodand so forth regarding a region of the MMR #2 which is the transmissiondata to the relay station 3 (including MAP (map) data, transmission dataand so forth destined for the radio terminal 4-2) and data for thenotification of a transmission timing and a transmission channel (areception timing and a reception channel to the reception side), a radiocommunication method and so forth regarding the region of the T4-1 whichis the transmission data for the radio terminal 4-1. It is to be notedthat also the controlling data in a region of the MMR #1 in FIG. 2 whichis the transmission data to the relay station not shown in FIG. 1 isincluded in the DL MAP (map).

On the other hand, the UL MAP (map) data includes MAP (map) data for thenotification of a region (a reception timing and a reception channel (atransmission timing and a transmission channel to the transmissionside)) for receiving an RNG (Ranging (ranging) signal) and a CQI(Channel Quality Indicator) from the radio terminal 4, a radiocommunication method and so forth, and MAP (map) data for thenotification of a region (a reception timing and a reception channel (atransmission timing and a transmission channel to the transmissionside)) for receiving the MMR #2 (MMR #1 from a relay station not shown)from the relay station 3, a radio communication method and so forth.

Here, the Ranging (ranging) signal is a known signal and is received bythe radio station 2 (or by the radio base station 2 through the relaystation 3). The radio station 2 which receives the ranging signalreports a result obtained by determining not only a difference of areception timing (phase shift) and a difference of a reception frequencybut also information of increase or decrease of required transmissionpower as Adjustment (adjustment) information to the radio base station2. In this example, the RNG from the radio terminal 4-1 is directlyreceived within an RNG reception period of the radio base station 2 andthe RNG from the radio terminal 4-2 is received within an RNG receptionperiod of the relay station 3, and the RNGs are transmitted to the radiobase station 2 through the MMR #2 of an upward link.

The CQI indicates a transmission period for reporting a result obtainedby carrying out measurement of the reception quality such as a CINR(Career to Interference and Noise Ratio) or the like for a known signalsuch as a preamble, a pilot signal (known signal included in downwardburst data or the like) or the like by the radio terminal 4. The radiobase station 2 changes transmission parameters such as a modulationmethod, a coding method, a coding rate and so forth, for example, basedon the CQI information received from the radio terminal 4-1 under theradio base station 2 itself.

In particular, control in a direction in which the transmission speed israised is carried out where the reception quality is good, but controlin another direction in which the transmission speed is lowered iscarried out where the reception quality is degraded.

Incidentally, the relay station 3 transmits the preamble and the DL/ULMAP (map) in order to provide a service to the radio terminal 4-2outside the area where the radio base station 2 forms such as a radioterminal 4-2 shown in FIG. 1. In particular, since the radio terminal4-2 cannot receive the preamble and so forth transmitted from the radiobase station 2, by receiving the preamble and so forth transmitted fromthe relay station 3, the radio terminal 4-2 can be synchronized with aradio frame transmitted from the relay station 3. It is to be notedthat, as the preamble transmitted from the relay station 3, not only apreamble same as that transmitted from the radio base station 2 but alsoanother preamble different from that transmitted from the radio basestation 2 may be used.

The DL/UL MAP (map) transmitted from the relay station 3 defines aregion (transmission and reception timings and channels) and a radiocommunication method for carrying out radio communication with the radioterminal 4-2 under the relay station 3 and originates from the datatransmitted with the MMR #2 of the downward link, and the DL/UL MAP(map) can be set so as to have contents different from those of theDL/UL MAP (map) transmitted from the radio base station 2.

Accordingly, since the radio terminal 4-2 receives the preamble (P)transmitted from the relay station 3 to establish synchronization andthe DL MAP (map) to detect the transmission region and the radiocommunication method of the downward burst T4-2, the radio terminal 4-2receives the burst T4-2 with the region and the radio communicationmethod. Similarly, the radio terminal 4-2 acquires the transmissionregion and the radio communication method of the RNG, CQI and T4-2included in the received UL MAP (map).

Then, the relay station 3 receives the RNG, CQI and T4-2 in accordancewith the notified UL MAP (map) and transmits the received data to theradio base station 2 through the MMR #2 of the upward link.

In this manner, while the radio communication of the radio terminal 4-2can be supported by installing the relay station 3, the radio basestation 2 receives, in order to produce not only the DL/UL MAP (map) forthe communication with the radio terminal 4-1 and the relay station 3but also the DL/UL MAP (map) for the radio terminal 4-2, the informationof the radio terminal 4-2 received by the relay station 3.

In the present embodiment, the information amount to be transmitted bythe MMRs #2 of the upward/downward links between the relay station 3 andthe radio base station 2 can be suppressed.

[b] Description of the First Embodiment

Outline of a Signal Sequence in the First Embodiment

FIG. 3 is a view illustrating a signal sequence regarding a BW RequestCode (request code) and a response signal to the request code signaledfrom the radio base station 2 according to the first embodiment of thepresent invention, and FIG. 4 is a view illustrating a signal sequenceas a comparative example to the signal sequence of the first embodiment.It is to be noted that, in FIGS. 3 and 4, it is assumed that the relaystations 3 and 3′ are individually connected to three radio terminals4-21 to 4-23.

It is to be noted that the BW Request Code (request code) is a code tobe transmitted, when data should be transmitted from the radio terminal4 to the network, at first from the radio terminal 4 to the radio basestation 2 (through the relay station 3′ in FIG. 4 or the relay station 3in FIG. 3), for example, in the RNG region of the upward link in FIG. 2.The radio terminal selects one of plural kinds of codes and transmitsthe selected code. Then, a CDMA Allocation (allocation) IE which is aresponse to the BW Request Code (request code) is information defined inthe UL MAP (map) and is used for the notification of a frame region(transmission and reception timings) and a communication method forsignaling the BW Request from the radio terminal 4, to the radioterminal 4 which transmitted the BW Request Code (request code). Theradio terminal 4 which receives the CDMA Allocation (allocation) IE cantransmit the BW Request which is a band request for transmitting data tothe network with the frame region (transmission timing) and thecommunication method designated by the CDMA Allocation (allocation) IE,to the radio base station 2.

Here, in order for the radio base station 2 to carry out band allocationcorresponding to the BW Request Code (request code) through the UL MAP(map) as in the relay station 3′ shown in FIG. 4, it is supposed that,when BW Request Codes (request codes) #1 to #3 are received from theplural radio terminal 4-21 to 4-23, it becomes necessary upon everyreception to relay information (for example, the kind of the code) ofthe BW Request Codes (request codes) to the radio base station 2together with information of the reception timings (frame number, frameposition).

In particular, the radio base station 2′ shown in FIG. 4 receives theinformation relating to the BW Request Code (request code) every time,and produce scheduling information (DL/UL MAP (map)) including responses(CDMA Allocation (allocation) IEs (Information Elements); which aredescribed each as CDMA Alloc IE in FIG. 4) to the BW Request Codes(request codes).

On the other hand, with the relay station 3 according to the firstembodiment shown in FIG. 3, in order to produce scheduling informationin the radio base station 2 where the BW Request Codes (request codes)#1 to #3 are received from the radio terminals 4-21 to 4-23,respectively, information intensively collected rather than allinformation in the case of FIG. 4 is transmitted as a single BW RequestMessage (request message) to the radio base station 2 withouttransmitting all information of the BW Request Codes (request codes) #1to #3 including the information of the reception timings (that is,information of the transmission timings from the radio terminal).

In particular, when the BW Request Codes (request codes) #1 to #3 arereceived from the plural connected radio terminals 4-21 to 4-23,respectively, the relay station 3 stores the BW Request Codes (requestcodes) #1 to #3 and information of the reception position of the BWRequest Codes (request codes) in radio frames (information obtained byreception of signals from the radio terminals). Then, the relay station3 transmits, as information obtained by intensively collecting theinformation of the BW Request Codes (request codes), for example, notpatterns of the received BW Request Codes (request codes) themselves butinformation of the number of the received BW Request Codes (requestcodes) as the BW Request Message (request message) to the radio basestation 2. It is to be noted that transmission of the information of thereception timings of the BW Request Codes (request codes) #1 to #3stored by the relay station 3 itself to the radio base station 2 isomitted.

The radio base station 2 secures the number of regions for CDMAAllocation (allocation) IEs equal to the number of the BW Request Codes(request codes) received from the relay station 3 and produces the ULMAP (map). In particular, the radio base station 2 does not carry outthe particular information of the reception frame position of the BWRequest Code (request code) individually in the CDMA Allocation(allocation) IEx3 which are responses to the radio terminals 4-21 to4-23 which transmitted the BW Request Codes (request codes) #1 to #3,respectively, but outputs a response R1 (CDMA Allocation (allocation) IEin the UL MAP (map)) representing that regions for the allocation aresecured. Normally, while the value of the BW Request Codes (requestcodes) and the position of radio frames when the radio terminals 4-21 to4-23 transmit the BW Request Codes (request codes) #1 to #3,respectively, are described in the CDMA Allocation (allocation) IE,since the radio base station 2 in the first embodiment does not graspthe information just described, the description of the information intothe region is omitted.

In particular, the positions, which are to be written into the CDMAAllocation (allocation) IEs, of the radio frames when the radioterminals 4-21 to 4-23 transmit the BW Request Codes (request codes) #1to #3, respectively, are stored in the relay station 3 as describedabove. Therefore, the relay station 3 writes the contents of theinformation stored therein into the CDMA Allocation (allocation) IEregion in the UL MAPs (maps) from the radio base station 2 and allocatesthe frame positions of the BW Requests individually. It is to be notedthat the priority degree of the allocation can be determined using thearrival order, the degree of importance or the like of the Codes as ascale.

The relay station 3 transmits the CDMA Allocation (allocation) IEs #1 to#3 as responses in which the frame positions of the BW Requests areallocated in this manner in the UL MAP (map) (refer to R2). The radioterminals 4-21 to 4-23 can read out the contents of the response CDMAAllocation (allocation) IEs #1 to #3 corresponding to the BW RequestCodes (request codes) #1 to #3 transmitted from the radio terminals 4-21to 4-23 themselves from the contents of the received UL MAPs (maps),respectively, so that each of them can obtain the frame position and theradio communication method designated for transmitting a later BWRequest.

Consequently, the transmission amount of the information relating to theBW Request Code (request code) particularly from the relay station 3 tothe radio base station 2 can be reduced and the MMR #2 which is a radiocommunication resource of the upward link can be effectively used.

Configuration of the Relay Station in the First Embodiment

Taking notice of such a function for achieving enhancement of efficiencyof a radio communication resource as described above, the relay station3 in the first embodiment includes a reception section 301, a Codereception section 302, a storage section 303, an intensive collectionsection 304, a notification section 305, a transmission section 306, aUL MAP (map) extraction section 307 and a relay section 308 similarly toa relay station 3A shown in FIG. 5.

Here, the reception section 301 receives a signal or a radio signalwhich forms a message from the radio terminal 4-2 (refer to FIG. 1,radio terminals 4-21 to 4-23 in FIG. 3) and the radio base station 2.Further, the Code reception section 302 extracts a code (Code) like, forexample, such a BW Request Code (request code) (band request signal)from the radio terminal 4-2 as described above from the signal or themessage received by the reception section 301. In particular,information of a symbol (symbol) and a subchannel (subchannel) isdetected as information of a frame number, a code value and a positionof a radio frame when the code is received.

Accordingly, a terminal side signal reception section for receivingsignals and messages from the plural radio terminals 4-21 to 4-23 andstoring information of the received signals and messages into thestorage section 303 is configured from the reception section 301 and theCode reception section 302 described above. Further, a base station sidesignal reception section for receiving scheduling information incommunication between the radio base station 2A and the plural radioterminals 4 through the relay station 3A from the radio base station 2Ais configured from the reception section 301 described above.

The storage section 303 stores the information of the signals and themessages from the plural radio terminals 4-21 to 4-23. In particular, asthe information of the band request signal received by the Codereception section 302, information of the kind and the position of theband request signals is stored as communication controlling informationby the storage section 302. For example, as shown in FIG. 6, theinformation of the code number and frame number extracted and detectedby the Code reception section 302 and the symbol and the sub channelwhich are information of the position of the radio frame when the codeis received is stored. Further, the storage section 303 stores thecommunication controlling information for controlling communication withthe plural radio terminals 4-21 to 4-23 (in this instance, informationfor producing a DL/UL MAP (map) which is scheduling information).

The intensive collection section 304 intensively collects theinformation of the signals and the messages from the plural radioterminals 4-21 to 4-23. In particular, where such a BW Request Code(request code) from the radio terminal 4-2 as described above isreceived by the Code reception section 302, the number of such BWRequest Codes (request codes) received in the frame is counted andinformation of the counted number of the BW Request Codes (requestcodes) is passed to the notification section 305 so as to be signaled asa controlling message to the radio base station 2A.

Consequently, the notification section 305 produces a controllingmessage based on the information of the number of the BW Request Codes(request codes) from the intensive collection section 304, and thetransmission section 306 radio transmits the controlling messageproduced by the notification section 305 to the radio base station 2A.It is to be noted that a band for transmission of the controllingmessage is allocated by the radio base station 2A when the relay station3A receives the BW Request Code (request code) from the radio terminal4-2.

An example of a configuration of the controlling message to be producedby the notification section 305 is illustrated in FIG. 7. As illustratedin FIG. 7, ID information (RS ID) of the relay station 3A which isidentification information of the transmission source, information of akind (type) of the controlling message (Message Type), a frame number(Frame Number) when the relay station 3A receives the BW Request Code(request code) and a count value (No. BW Request Code) of the number ofthe BW Request Codes (request codes) at that time can be included in thecontrolling message.

Accordingly, a base station side signal transmission section fortransmitting information intensively collected by the intensivecollection section 304 to the radio base station 2A in order to producea DL/UL MAP (map) which is scheduling information is composed from thenotification section 305 and the transmission section 306 describedabove.

Further, the UL MAP (map) extraction section 307 extracts the UL MAP(map) from the signal received from the radio base station 2A by thereception section 301.

The CDMA Allocation (allocation) IE which is a response to the BWRequest Code (request code) is included in the UL MAP (map). When therelay section 308 relays the UL MAP (map) extracted by the UL MAP (map)extraction section 307 to the radio terminal 4-2 through thetransmission section 306, particularly the information of the CDMAAllocation (allocation) IE is converted into the information stored inthe storage section 303

As described above, while the information of the position, frame number,code value and so forth of the radio frame when the radio terminals 4-21to 4-23 transmit the BW Request Codes (request codes) #1 to #3 arestored into the storage section 303 of the relay station 3A, by theintensive collection process by the intensive collection section 304,the information stored in the storage section 303 is omitted from thecontents (contents of the controlling message of FIG. 7) to be signaledto the radio base station 2A. Accordingly, the information justdescribed is not included in the CDMA Allocation (allocation) IEincluded in the UL MAP (map) from the radio base station 2A.

The relay section 308 can write to complement the contents (informationof the position, frame number, code value and so forth of the radioframe) stored in the storage section 303 into the region of the CDMAAllocation (allocation) IE in the UL MAP (map) extracted by the UL MAP(map) extraction section 307, and can individually allocate a frameposition of a BW Request to be transmitted from the radio terminal 4-2.The CDMA Allocation (allocation) IE whose contents are complemented inthis manner can be transmitted to the radio terminal 4 through thetransmission section 306. It is to be noted that the priority degree ofthe allocation can be determined using the arrival order of the Codes,the degree of importance or the like as a scale.

Accordingly, a complementation section for complementing the contents ofthe scheduling information (from the radio base station 2A) received bythe reception section 301 in accordance with the communicationcontrolling information stored in the storage section 303 is configuredby the relay section 308 described above. In particular, the relaysection 308 as the complementation section complements the kind of theband request signal and the position information stored in the storagesection 303 regarding the scheduling information received by thereception section 301.

Further, the transmission section 306 configures a terminal side signaltransmission section for transmitting the scheduling information whosecontents are complemented by the relay section 308 to the plural radioterminals 4-21 to 4-23.

Configuration of the Radio Base Station 2A in the First Embodiment

Further, taking notice of the function for achieving enhancement of theefficiency of such a communication resource as described above, theradio base station 2A in the first embodiment includes a receptionsection 201, a controlling message extraction section 202, a schedulingsection 203, an NW interface section 204, a buffer section 205 and atransmission section 206 as shown in FIG. 8.

Here, the reception section 201 receives a radio signal which configuresa signal or a message from the relay station 3A or the radio terminal4-1 (refer to FIG. 1). Further, the controlling message extractionsection 202 extracts information of the controlling message from thesignal or the message received by the reception section 201. Forexample, the controlling message extraction section 202 extractscontents of the controlling message for the notification of the numberof such BW Request Codes (request codes) received by the relay station3A as illustrated in FIG. 7.

The scheduling section 203 produces a DL/UL MAP (map) which is thescheduling information from the contents described in the controllingmessage extracted by the controlling message extraction section 202. Forexample, where such a controlling message for the notification of thenumber of the BW Request Codes (request codes) as illustrated in FIG. 7is extracted by the controlling message extraction section 202, thescheduling section 203 produces CDMA Allocation (allocation) IEs for thenumber of regions equal to the number of the BW Request Codes (requestcodes) and adds the produced CDMA Allocation (allocation) IEs to the ULMAP (map). At this time, the produced CDMA Allocation (allocation) IEdoes not include particular information which configures a response tothe BW Request Codes (request codes).

Accordingly, the scheduling section 203 described above functions as ascheduling information production section for producing a DL/UL MAP(map) which is the scheduling information based on the informationreceived by the reception section 201 except for information to becomplemented by the relay section 308 of the relay station 3A describedabove. In other words, the scheduling section 203 carries out, based onthe information received by the reception section 201, allocation of thenumber of bands equal to the number of band request signals intensivelycollected in the information received by the reception section 201 toproduce scheduling information.

The NW interface section 204 carries out an interface process forsignaling the data from the radio terminal 4 received by the receptionsection 201, for example, to a different network, and carries outanother interface process for a signal destined for the radio terminal 4from the different network. Further, the buffer section 205 carries outbuffering to transmit the data from the NW interface section 204 or theDL/UL MAP (map) produced by the scheduling section 203 from thetransmission section 206 at a predetermined timing.

The transmission section 206 transmits the signal or the message fromthe buffer section 205 to the relay station 3A or the radio terminal4-1. For example, the transmission section 206 transmits the schedulinginformation produced by the scheduling section 203 to the relay station3A.

Working Effect

Since the relay station 3A and the radio base station 2A in the firstembodiment are configured in such a manner as described above, forexample, as illustrated in the signal sequence of FIG. 3, the relaystation 3A can transmit the information of the BW Request Codes (requestcodes) #1 to #3 from the radio terminals 4-2 as an intensively collectedcontrolling message to the radio base station 2A and transmit a CDMAAllocation (allocation) IE from the radio base station 2A to the radioterminals 4-2 while complementing the contents of the CDMA Allocation(allocation) IE.

In particular, the reception section 301 and the Code reception section302 of the relay station 3A receive BW Request Codes (request codes) assignals or messages from the plural radio terminals 4-21 to 4-23 andstore the information of the code number, frame position and framenumber which are information of the received BW Request Codes (requestcodes) as communication controlling information for communicationcontrol between the relay station 3A and the radio terminals 4-21 to4-23 into the storage section 303. Further, the intensive collectionsection 304 intensively collects the information of the BW Request Codes(request codes) from the radio terminals 4-21 to 4-23, and thenotification section 305 and the transmission section 306 transmit theintensively collected information to the radio base station 2A (refer to“BW Request Message (request message)” in FIG. 3 and refer to FIG. 7).

Further, in the radio base station 2A, the reception section 201 and thecontrolling message extraction section 202 receive the intensivelycollected information described above from the relay station 3A, and thescheduling section 203 produces scheduling information (CDMA Allocation(allocation) IE of the UL MAP (map)) for communication between the radiobase station 2A and the individual radio terminals 4-21 to 4-23 throughthe relay station 3A based on the received intensively collectedinformation. Further, the buffer section 205 and the transmissionsection 206 transmit the scheduling information produced as justdescribed to the relay station 3A (refer to reference character R1 inFIG. 3). At this time, particular information which forms a response tothe BW Request Code (request code) is not included in the CDMAAllocation (allocation) IE which forms the produced schedulinginformation (in other words, the portion is left as a blank space).

The scheduling information transmitted from the radio base station 2A isreceived by the reception section 301 and the UL MAP (map) extractionsection 307 of the relay station 3A, and the contents of the receivedscheduling information are complemented by the relay section 308 inaccordance with the communication controlling information stored in thestorage section 303 (in other words, particular information whichconfigures a response to the BW Request Codes (request codes) isincorporated). Then, the scheduling information whose contents arecomplemented is transmitted to the radio terminals 4-21 to 4-23 by thetransmission section 306 (refer to reference character R2 of FIG. 3)

It is to be noted that each of the radio terminals 4-21 to 4-23 extractsthe CDMA Allocation (allocation) IE which is a response to the BWRequest Code (request code) transmitted from the radio terminal itselffrom the frame position information and the CDMA code information in theCDMA Allocation (allocation) IE in the received UL MAP (map).Consequently, the radio terminals 4-21 to 4-23 can thereafter transmit aBW Request in a region designated in the Up Link Sub-frame in the UL MAP(map).

In this manner, with the first embodiment of the present invention,since the information of the UL MAP (map) corresponding to each of theradio terminals 4-21 to 4-23 can be complemented by the relay station3A, there is an advantage that effective utilization of the radiocommunication resource can be achieved.

It is to be noted that, while the case wherein the plural radioterminals 4-21 to 4-23 are accommodated in the relay station 3A isdescribed in the first embodiment described above, the present inventionis not limited to this, and, also in a case wherein one radio terminalis accommodated, effective utilization of the radio communicationresource can be achieved similarly as in the first embodiment.

[b] Description of the Second Embodiment of the Present Invention

While, in the first embodiment, the case is described wherein, where therelay station 3B is installed, the BW Request Code (request code) istransmitted as a band request signal from a radio terminal 4-2 and theCDMA Allocation (allocation) IE in the UL MAP (map) is transmitted as aresponse from the radio base station 2B, in the second embodiment, acase is described wherein a Ranging Code (ranging code) is transmittedfrom a radio terminal 4-2 and an RNG-RSP in the DL MAP (map) istransmitted as a response from the radio base station 2B.

It is to be noted that the Ranging Code (ranging code) is a code whichis transmitted from the radio terminal 4-1 to the radio base station 2Bshown in FIG. 1 to allow the radio terminal 4-1 to receive aninstruction (RNG-RSP) for controlling the transmission power,transmission timing and transmission frequency in the radio terminal 4-1from the radio base station 2B.

Where the relay station 3B is installed as in the present embodiment, aradio terminal 4-2 which exists within the cover area of the relaystation 3B but outside the cover area of the radio base station 2Btransmits the Ranging Code (ranging code) at a stage at which radioconnection to the relay station 3B starts, and receives transmissionpower control and so forth through a response (RNG-RSP) from the relaystation 3B. At this time, it is necessary to receive allocation of aband through a DL MAP (map) from the radio base station 2B in order thatthe relay station 3B transmits the RNG-RSP to the radio terminal 4-2.Accordingly, it is necessary for the relay station 3B to transmitinformation regarding the Ranging Code (ranging code) from the radioterminal 4-2 to the radio base station 2B.

Here, where the relay station 3B is installed, it is estimated that, ifthe relay station 3B receives the Ranging Codes (ranging codes) #1 to #3from the plural radio terminals 4-21 to 4-23, then, in order for theradio base station 2B to carry out band allocation corresponding to theRanging Codes (ranging codes) through the DL MAP (map), it becomesnecessary every time of reception each Ranging Code (ranging code) torelay the information of the Ranging Code (ranging code) to the radiobase station 2B together with the information of the reception timing(frame number, frame position).

On the other hand, in the second embodiment, it is anticipated that theinformation regarding the Ranging Code (ranging code) to be transmittedfrom the relay station 3B to the radio base station 2B is intensivelycollected and the relay station 3B produces an RNG-RSP to effectivelyutilize a band as hereinafter described.

Outline of a Signal Sequence in the Second Embodiment

FIG. 9 is a view illustrating a signal sequence regarding Ranging Codes(ranging codes) signaled from the radio terminals 4-21 to 4-23 andresponse signals to the Ranging Codes (ranging codes). When the RangingCodes (ranging codes) #1 to #3 are received from the radio terminals4-21 to 4-23, respectively, not all information of the Ranging Codes(ranging codes) #1 to #3 including information regarding the receptionti ing (in other words, information regarding the transmission timingfrom each radio terminal 4) is transmitted in order to allow the radiobase station 2B to produce a DL MAP (map) described above, butintensively collected information rather than all information regardingthe Ranging Code (ranging code) is transmitted as a single RS RangingMessage (ranging message) to the radio base station 2B similarly as inthe case of FIG. 3 of the first embodiment.

In particular, where the Ranging Codes (ranging codes) #1 to #3 arereceived from the plural radio terminals 4-21 to 4-23 connected to therelay station 3B, respectively, the relay station 3B stores adjustmentinformation such as the power, timing, frequency and so forth(controlling information for adjusting the transmission power, timingand frequency from the radio terminals 4-21 to 4-23) to the radioterminal 4-21 to 4-23 together with the Ranging Codes (ranging codes) #1to #3 and information of the reception positions of the Ranging Codes(ranging codes).

Then, the relay station 3B transmits, for example, following the case ofthe first embodiment, not patterns of the received Ranging Codes(ranging codes) themselves but information of the number of the receivedRanging Codes (ranging codes) as the RS Ranging Message (rangingmessage) to the radio base station 2B. It is to be noted thattransmission of the information, for adjusting the reception timings,power and so forth of the Ranging Codes (ranging codes) #1 to #3 storedin the relay station 3B itself as described above, to the radio basestation 2B is omitted.

The radio base station 2B secures the number of regions for the RNG-RSPequal to the number of the Ranging Codes (ranging codes) received fromthe relay station 3B within a data region in the frame to produce a DLMAP (map). In particular, the radio base station 2B designates regionsfor the RNG-RSPs in the DL MAP (map) as responses R3 to the radioterminals 4-21 to 4-23 from which the Ranging Codes (ranging codes) #1to #3 have been transmitted, respectively. It is to be noted that, sincethe radio base station 2B has not received the controlling informationsuch as the transmission power, transmission timing and so forth fromthe relay station 3B, individual writing of the controlling informationis not carried out for the designated regions RNG-RSP.

In particular, the transmission power controlling information and thephase controlling information or the frequency controlling information,which are to be written into the RNG-RSPs, for the radio terminals 4-21to 4-23 are stored in the relay station 3B as described above.Therefore, the relay station 3B writes the contents of the informationinto the RNG-RSP regions designated by the DL MAP (map) and issuesnotifications of the transmission power controlling information, thecontrolling information of the transmission timing (phase) so forth asthe RNG-RSPs #1 to #3 to the radio terminals 4-21 to 4-23, respectively.

Consequently, the transmission amount of the information regarding theRanging Code (ranging code) particularly from the relay station 3B tothe radio base station 2B can be reduced and the MMR #2 which is a radiocommunication resource of the upward link can be used efficiently.

Configuration of the Relay Station in the Second Embodiment

Taking notice of such a function for achieving enhancement of theefficiency of a radio communication resource as described above, therelay station 3B in the second embodiment includes a reception section311, a Code reception section 312, a storage section 313, an intensivecollection section 314, a notification 315, a transmission section 316,a DL MAP (map) extraction section 317 and a relay section 318 similarlyto the relay station 3B shown in FIG. 10.

Here, the reception section 311 receives a radio signal which configuresa signal or a message from the radio terminal 4-2 (refer to FIG. 1, anyof the radio terminals 4-21 to 4-23 in FIG. 9) and the radio basestation 2B. Meanwhile, the Code reception section 312 extracts, forexample, a code (Code) such as a Ranging Code (ranging code) from theradio terminal 4-2 described above from the signal or the messagereceived by the reception section 311.

In particular, the Code reception section 312 detects a frame number anda code value when a code is received, and detects information of asymbol (symbol) and a sub channel (subchannel) as position informationof the radio frame when the code is received. Particularly, where thereception section 311 receives the Ranging Codes (ranging codes) fromthe radio terminals 4-21 to 4-23, the Code reception section 312measures the reception power and the reception timings from thereception signals of the Ranging Codes (ranging codes) and stores powerand timing adjustment information to the radio terminals 4-2 producedbased on a result of the measurement into the storage section 313.

Accordingly, a terminal side signal reception section for receivingsignals and messages from the plural radio terminals 4-21 to 4-23 andstoring the information of the received signals and messages into thestorage section 313 is configured from the reception section 311 and theCode reception section 312 described above. Particularly, the Codereception section 312 receives the Ranging Codes (ranging codes) whichare power/timing adjustment signals from the plural radio terminals 4-21to 4-23 and produces power/timing adjustment information for thecorresponding radio terminals 4-21 to 4-23 from the received RangingCodes (ranging codes) and then stores the kind (code kind) informationand the position information as the Ranging Codes (ranging codes) ascommunication controlling information into the storage section 313together with the produced power/timing adjustment information.

Further, a base station side signal reception section for receivingscheduling information (DL/UL MAP (map)) in the communication betweenthe radio base station 2B and the individual plural radio terminals 4-21to 4-23 through the relay station 3B from the radio base station 2B isconfigured from the reception section 311 described above.

Furthermore, the storage section 313 stores communication controllinginformation (in this instance, information for producing the DL/UL MAP(map) which is scheduling information) for controlling communicationwith the plural radio terminals 4-21 to 4-23. In particular, asillustrated in FIG. 11, a code number (Code) and a frame number (FrameNumber) extracted and detected by the Code reception section 312 andinformation of a symbol (Symbol) and a sub channel (Subchannel) whichare information of the position of the radio frame when the code isreceived are stored as information relating to the Ranging Code (rangingcode) received by the Code reception section 312, and timing adjustmentinformation (Timing) and power adjustment information (Power) are storedas power/timing adjustment information.

The intensive collection section 314 intensively collects thepower/timing adjustment signals from the plural radio terminals 4-21 to4-23 to be transmitted to the radio base station 2B. In particular,where the Code reception section 312 receives the Ranging Codes (rangingcodes) which are such power/timing adjustment signals from the radioterminals 4-21 to 4-23 as described above, the number of the RangingCodes (ranging codes) received within the frame is counted and theinformation of the counted number of the Ranging Codes (ranging codes)is passed to the notification section 315 so as to be transmitted as acontrolling message to the radio base station 2.

Consequently, the notification section 315 produces a controllingmessage based on the information of the number of the Ranging Codes(ranging codes) from the intensive collection section 314, and thetransmission section 316 transmits the controlling message produced bythe notification section 315 to the radio base station 2. It is to benoted that a band for transmission of the controlling message isallocated by the radio base station 2B when the relay station 3Breceives the Ranging Code (ranging code) from the radio terminal 4-2.

An example of the configuration of the controlling message to beproduced by the notification section 315 is illustrated in FIG. 12. Asillustrated in FIG. 12, ID information of the relay station 3B which isidentification information of the transmission source (RS ID),information of the kind (type) of the controlling message (MessageType), the frame number when the relay station 3B receives the RangingCode (ranging code) (Frame Number) and the count value of the number ofthe Ranging Codes (ranging codes) at the time (No. Ranging Code) can beincluded in the controlling message.

Accordingly, a base station side signal transmission section fortransmitting information intensively collected by the intensivecollection section 314 to the radio base station 2 in order to produce aDL/UL MAP (map) which is scheduling information is configured from thenotification section 315 and the transmission section 316 describedabove.

Further, the DL MAP (map) extraction section 317 extracts the DL MAP(map) from the signal from the radio base station 2 received by thereception section 311.

The power and timing adjustment information for the Ranging Code(ranging code) is written into the RNG-RSP whose region is designated bythe DL MAP (map). Then, while the relay station 318 relays the DL MAP(map) extracted by the DL MAP (map) extraction section 317, regardingthe information (symbol and sub channel) of the position of the radioframe originating particularly from the radio terminal which hastransmitted the code, the DL MAP (map) is complemented with the contentsstored in the storage section 313. Further, the relay section 318 writesthe power/timing adjustment information to the radio terminals 4-21 to4-23 into the RNG-RSP designated by the DL MAP (map). The signal intowhich the contents of the DL MAP (map) and the RNG-RSP are written inthis manner is transmitted to the radio terminals 4-21 to 4-23 throughthe transmission section 316.

As described above, the position information, frame number, code valueand so forth of a radio frame when the radio terminals 4-21 to 4-23transmit the Ranging Codes (ranging codes) are stored into the storagesection 313 of the relay station 3B, but are omitted from the contentsto be transmitted to the radio base station 2B (contents of thecontrolling message in FIG. 12).

The relay station 318 writes the contents (information of the position,frame number, code value and so forth of the radio frame) stored in thestorage section 313 to complement the contents of the DL MAP (map)extracted by the DL MAP (map) extraction section 317, and writes thepower/timing adjustment information to the radio terminals 4-21 to 4-23into the RNG-RSP region designated by the DL MAP (map) described above.

Accordingly, a complementation section for complementing the contents ofscheduling information (from the radio base station 2B) received by thereception section 311 in accordance with communication controllinginformation stored in the storage section 313 is configured by the relaysection 318 described above. In other words, the relay section 318 asthe complementation section complements the RNG-RSP designated by the DLMAP (map) received by the reception section 311 using kind informationand position information of the power/timing adjustment signal stored inthe storage section 313.

Further, the transmission section 316 as the terminal side signaltransmission section transmits the DL MAP (map) which is schedulinginformation whose contents are complemented by the relay section 318 andtransmits the power/timing adjustment information produced by the Codereception section 312 to the plural radio terminals 4-21 to 4-23 throughthe RNG-RSP.

Consequently, the radio terminals 4-21 to 4-23 can extract thepower/timing adjustment information corresponding to the Ranging Codes(ranging codes) transmitted individually from the radio terminals fromthe RNG-RSP referring to the DL MAP (map) and transmit a signal with thetransmission power and at the timing based on the extracted adjustmentinformation.

Configuration of the Radio Base Station 2B in the Second Embodiment

Further, taking notice of such a function for achieving enhancement ofefficiency of a radio communication resource as described above, theradio base station 2B in the second embodiment includes a receptionsection 211, a controlling message extraction section 212, a schedulingsection 213, an NW interface section 214, a buffer section 215 and atransmission section 216 as shown in FIG. 13.

Here, the reception section 211 receives a radio signal which configuresa signal or a message from the relay station 3B or the radio terminal4-1 (refer to FIG. 1) and receives information from the transmissionsection 316 which configures the base station side signal transmissionsection in the relay station 3B. Further, the controlling messageextraction section 212 extracts information of the controlling messagefrom within the signal or the message received by the reception section211. For example, the controlling message extraction section 212extracts the contents of the controlling message for the notification ofsuch number of the Ranging Codes (ranging codes) as shown in FIG. 12from the relay station 3B.

The scheduling section 213 produces a DL/UL MAP (map) which isscheduling information from the contents described in the controllingmessage extracted by the controlling message extraction section 212. Forexample, when the controlling message extraction section 212 extractssuch a controlling message for the notification of the number of RangingCodes (ranging codes) as shown in FIG. 12, the scheduling section 213secures the number of RNG-RSPs equal to the number of the Ranging Codes(ranging codes) based on the DL MAP (map). At this time, the informationof the position, the frame number, the code value and so forth of theradio frame are not described in the DL MAP (map), and particularpower/timing adjustment information which makes a response to theRanging Codes (ranging codes) is not included in the RNG-RSPs.

Accordingly, the scheduling section 213 described above functions as ascheduling information production section for producing a DL MAP (map)which is scheduling information except for information to becomplemented by the relay section 318 of the relay station 3B describedabove based on a message for the notification of the number of RangingCodes (ranging codes) received by the reception section 211. In otherwords, the scheduling section 213 carries out, based on the informationreceived by the reception section 211, allocation of the number of bandsequal to the number of the Ranging Codes (ranging codes) intensivelycollected to the information received by the reception section 211 toproduce a DL MAP (map) which is scheduling information.

The NW interface section 214 carries out an interface process in orderto signal the data from the radio terminal 4 received by the receptionsection 211, for example, to a different network and carries out anotherinterface process for a signal from the different network destined for aradio terminal 4. Further, the buffer section 215 carries out bufferingfor data from the NW interface section 214 or a DL/UL MAP (map) producedby the scheduling section 213 in order to allow transmission of the dataor the DL/UL MAP (map) from the transmission section 216 at apredetermined timing.

The transmission section 216 transmits a signal or a message from thebuffer section 215 to the relay station 3B or the radio terminal 4-1. Inparticular, the transmission section 216 transmits the DL MAP (map)which is produced by the scheduling section 213 as described above andwherein a region within a RNG-RSP is designated as described above tothe relay station 3B or the terminal 4-1.

Working Effect

In the second embodiment, since the relay station 3B and the radio basestation 2B are individually configured in such a manner as describedabove, for example, as illustrated in the signal sequence of FIG. 9, therelay station 3B can transmit a controlling message wherein informationof the Ranging Codes (ranging codes) #1 to #3 from the radio terminals4-21 to 4-23 is intensively collected to the radio base station 2B, andcan transmit power/timing adjustment information corresponding to theindividual radio terminals 4-21 to 4-23 in RNG-RSP whose region isdesignated by a DL MAP (map) from the radio base station 2B whilecomplementing the contents of the DL MAP (map) and RNG-RSP.

In particular, if the reception section 311 and the Code receptionsection 312 of the relay station 3B receive, for example, Ranging Codes(ranging codes) as signals and messages from the plural radio terminals4-21 to 4-23, then information of the code number, frame position andframe number which is information of the received Ranging Codes (rangingcodes) is stored as communication controlling information for thecommunication control between the radio terminals 4-21 to 4-23 and therelay station 3B into the storage section 313. Further, the Codereception section 312 measures the reception power and the receptiontiming from the reception signal of the received Ranging Codes (rangingcodes) and stores power/timing adjustment information to the radioterminals 4-21 to 4-23 produced based on the result of the measurementinto the storage section 313.

Further, the intensive collection section 314 intensively collects theinformation of the Ranging Codes (ranging codes) from the radioterminals 4-21 to 4-23, and the notification section 315 and thetransmission section 316 transmit the intensively collected informationto the radio base station 2B (refer to “RS Ranging Message (rangingmessage)” in FIG. 9 and to FIG. 12).

Further, in the radio base station 2B, the reception section 211 and thecontrolling message extraction section 212 receive the intensivelycollected information described above from the relay station 3B, and thescheduling section 213 produces scheduling information (DL MAP (map))for the communication between the relay station 3B and the individualradio terminals 4-21 to 4-23 based on the received intensively collectedinformation. Then, the buffer section 215 and the transmission section216 transmit the scheduling information produced as described above tothe relay station 3B (refer to reference character R3 in FIG. 9). Atthis time, particular power/timing adjustment information as a responseto the Ranging Codes (ranging codes) is not included in the RNG-RSPwhose region is designated by the DL MAP (map), and the portion is leftsubstantially as a blank space.

The reception section 311 and DL MAP (map) extraction section 317 of therelay station 3B receive the scheduling information transmitted from theradio base station 2B, and the relay section 318 complements thecontents of the DL MAP (map) which is the received schedulinginformation in accordance with the communication controlling informationstored in the storage section 313 and writes the power/timing adjustmentinformation to the radio terminals 4-21 to 4-23 into the RNG-RSP. Then,the transmission section 316 transmits the power/timing adjustmentinformation to the radio terminals 4-21 to 4-23 through the RNG-RSPregions together with the scheduling information whose contents arecomplemented.

It is to be noted that each of the radio terminals 4-21 to 4-23 canextract the power/timing adjustment information corresponding to theRanging Code (ranging code) transmitted from the radio terminal from theRNG-RSP region while referring to the contents of the DL MAP (map), andtransmit a signal with transmission power and at a timing in accordancewith the extracted adjustment information.

In this manner, with the second embodiment of the present invention,there is an advantage that, since the relay station 3 can complementinformation of the DL MAP (map) corresponding to the radio terminals4-21 to 4-23 and write power/timing adjustment information into theRNG-RSP region, information to be transmitted to the radio base station2B can be reduced to achieve effective utilization of a radiocommunication resource.

It is to be noted that, while the case wherein the plural radioterminals 4-21 to 4-23 are accommodated by the relay station 3B isdescribed in the second embodiment described above, the presentinvention is not limited to this, and, also in a case wherein one radioterminal is accommodated, effective utilization of a radio communicationresource can be achieved similarly.

[c] Description of the Third Embodiment

In the third embodiment, a case is described wherein, in a radiocommunication system which includes a radio base station 2 and a radioterminal 4 and into which a relay station 3 is installed similarly as inthe cases of the first and second embodiments described above, a CQI(Channel Quality Indicator) report is received by the relay station 3.It is to be noted that the CQI report is used for the notification ofradio signal quality in the radio terminal 4-2 to the radio base station2 through the relay station 3. The radio base station 2 can receive theCQI report from the radio terminal 4-2 at fixed cyclical intervals andadaptively change over the radio communication method to an optimum onebased on the varying value of the CQI. For example, if the receptionquality is good, then a radio communication method suitable forhigh-speed communication can be applied, but, if the reception qualityis not good, then another radio communication method which has acomparatively high tolerance for a noise environment, although thecommunication speed, is low can be applied. It is to be noted that, forexample, as the CQI, a CINR (Career to Interference and Noise Ratio)which is a quality parameter value which can be measured withoutdecoding a reception signal is available.

Outline of a Signal Sequence in the Third Embodiment

FIG. 14 is a view illustrating a signal sequence regarding a CQI reportto be transmitted from the radio terminal 4-2 (refer to FIG. 1) and aresponse signal to the CQI report in the third embodiment of the presentinvention. As illustrated in FIG. 14, the relay station 3 carries out,when CQI reports PR1(Periodic Report) to RP4 received in a fixed periodfrom the connected radio terminal 4-2 are received, comparison for everytime of the reception with CQI report information in the precedingoperation cycle stored in the relay station 3. It is to be noted that,while description is given here taking notice of a case wherein a CQIreport is received from one radio terminal 4-2 connecting to the relaystation 3, the description applies similarly also to a case wherein aplurality of the radio terminals 4-2 are connected.

Then, only when it is decided from a result of the comparison that theradio communication method used between the relay station 3 and theradio terminal 4-2 is to be changed, the relay station 3 issues anotification of the information of the radio communication method to beused between the relay station 3 and the radio terminal 4-2 to the radiobase station 2. For example, the relay station 3 compares, based on thecontents of the CQI report PR3 from the radio terminal 4-2, the contentsof the CQI report RP3 with the contents of the CQI report received inthe past (for example, the CQI report PR2 in the preceding operationcycle) to decide whether or not the radio communication method is to bechanged and determine also a radio communication method after thechange. Then, the relay station 3 issues a notification of the changinginformation relating to the radio communication method (MS Burst ProfileInfo).

The radio base station 2 carries out scheduling based on the informationof the changed radio communication method from the radio terminals 4-21to 4-23 to produce a DL/UL MAP (map) and transmits the produced DL/ULMAP (map) to the relay station 3. Consequently, the information amountto be communicated between the relay station 3 and the radio basestation 2 is reduced to achieve effective utilization of a radiocommunication resource.

Configuration of the Relay Station in the Third Embodiment

Taking notice of such a function for achieving enhancement of theefficiency of a radio communication resource as described above, therelay station 3 in the third embodiment includes a reception section321, a CQI reception section 322, a storage section 323, a decisionsection 324, a notification section 325 and a transmission section 326similarly to the relay station 3C shown in FIG. 15.

Here, the reception section 311 receives a signal or a message from theradio terminal 4-2 and the radio base station 2. Further, the CQIreception section 322 extracts a CQI report which is a signal or amessage which indicates a state of the radio channel from the signal orthe message from the radio terminal 4-2 received by the receptionsection 321. Accordingly, the reception section 321 and the CQIreception section 322 described above configure a terminal sidereception section for receiving information of a signal and a messagereceived from a radio terminal.

The storage section 323 stores the contents of the CQI report from theradio terminal 4-2 received by the CQI reception section 322 for eachradio terminal 4-2. Information to be stored into the storage section323 is illustrated in FIG. 16. As illustrated in FIG. 16, the storagesection 323 stores, for each radio terminal 4-2 connected to the relaystation 3, also an MS ID which is ID information of the radio terminal,a CINR value and an index value of the radio communication method (BurstProfile) suitable for the CINR value through a writing action by thedecision section 324 hereinafter described.

Further, the decision section 324 decides based on the informationreceived by the CQI reception section 322 whether or not a notificationof relating information relating to the signal and the message receivedfrom the radio terminal 4-2 is to be issued to the radio base station 2.In particular, when the radio communication method to be used betweenthe relay station 3 and the radio terminal 4-2 need to be changed basedon the CQI information received by the CQI reception section 322, thatis, based on the information relating to the radio channel state betweenthe relay station 3 and the radio terminal 4-2, the decision section 324decides that a notification of the information relating to the radiochannel state is to be issued to the radio base station 2.

In particular, the decision section 324 first refers to a table notshown stored in the storage section 323 to extract and select a radiocommunication method suitable for the information received by the CQIreception section 322. In other words, for example, when the quality iscomparatively high in response to the CINR value, the decision section324 extracts and selects a radio communication method suitable forcomparatively high-speed transmission, but, when the quality iscomparatively low, the decision section 324 extracts and selects a radiocommunication method which is suitable for comparatively low-speedtransmission and besides has a comparatively high tolerance for noise.It is to be noted that, as the radio communication method to beselected, a modulation method, a coding method, a coding ratio and soforth can be used as parameters (factors).

Then, a difference between the radio communication method extracted andselected in this manner and the radio communication method extractedfrom the CINR value in the CQI report received last and stored in thestorage section 323 is decided. If the radio communication methods aredifferent from each other as a result of the decision, then it isdecided that the radio communication method used between the relaystation 3 and the radio terminal 4-2 needs to be changed to the newlyextracted and selected radio communication method, but, if the radiocommunication methods are same as each other as a result of thedecision, then it is decided that the radio communication method usedbetween the relay station 3 and the radio terminal 4-2 needs not to bechanged.

It is to be noted that, if such a decision regarding the radiocommunication method as described above ends, then the decision section324 can write, for every time of the end of the decision, the CINR valueand the extracted and selected radio communication method into thestorage section 323 in an associated relationship with the IDinformation of the corresponding radio terminal 4-2.

When it is decided by the decision section 324 that a notification ofthe changing information of the radio communication method which isinformation relating to the state of the radio channel received from theradio terminal 4-2 is to be issued to the radio base station 2 (that is,the radio communication method is to be changed), the notificationsection 325 produces, as a controlling message, the changing informationof the radio communication method as relating information and outputsthe produced information to the transmission section 326 at thefollowing stage. The transmission section 326 transmits the controllingmessage produced by the notification section 325 to the radio basestation 2. Accordingly, the changing information of the radiocommunication method described above is conveyed to the radio basestation 2 by cooperation of the notification section 325 and thetransmission section 326.

On the other hand, when it is decided by the decision section 324 that anotification of the changing information of the radio communicationmethod needs not to be issued (that is, the radio communication methodneed not to be changed), a notification of the changing information ofthe radio communication method as the relating information is not issuedthrough the notification section 325 and the transmission section 326.

FIG. 17 illustrates an example of information of a controlling messageto be transmitted from the relay station 3C to the radio base station 2for changing the radio communication method. The information of thecontrolling message can be configured from an ID of the relay station 3which indicates a transmission source of the controlling message (RSID), a type which indicates the present controlling message (MessageType), an ID of the radio terminal decided to be necessary to change theradio communication method (MS ID) by the decision section and an indexvalue of the radio communication method to be changed (Burst Profile).

It is to be noted that the radio base station 2 recognizes the radiocommunication method to be used between the relay station 3 and theradio terminal 4-2 based on the received controlling message andproduces a DL/UL MAP (map) based on the recognized radio communicationmethod.

Working Effect

Since the relay station 3C in the third embodiment is configured in sucha manner as described above, when the CQI reports PR1 to PR4 received atfixed intervals from the radio terminal 4-2 connected to the relaystation 3C are received, the relay station 3C may not transmit, forevery time of reception, the contents of the CQI report to the radiobase station 2 in order to produce a DL/UL MAP (map), but may transmitthe contents of the CQI report only when it decides to be necessary tochange the radio communication method based on the contents of the CQI.

In particular, the decision section 324 of the relay station 3C carriesout comparison between the CQI report information in the precedingoperation cycle stored in the storage section 323 and the radiocommunication method information obtained from the CQI report in thepresent operation cycle. Then, only when it is decided from a result ofthe comparison that the radio communication method to be used betweenthe relay station 3C and the radio terminal 4-2 is to be changed, anotification of the information of the radio communication method to beused between the relay station 3 and the radio terminal 4-2 is issued asa controlling message to the radio base station 2.

In this manner, with the third embodiment, since opportunities that therelay station 3C transmits a controlling message relating to thecontents of a CQI report transmitted from the radio terminal 4-2 can bereduced in comparison with those in a case wherein a controlling messageis transmitted for every time of reception of a CQI report, there is anadvantage that information to be signaled to the radio base station 2Bcan be reduced to achieve effective utilization of a radio communicationresource.

[b] Others

The present invention is not limited to the embodiments specificallydescribed above, and variations and modifications can be made withoutdeparting from the scope of the present invention.

For example, while, in the relay stations 3A and 3B in the first andsecond embodiments described above, the storage sections 303 and 313store information of a signal or a message in the upward direction fromthe radio terminal 4-2 as communication controlling information, thepresent invention is not limited to this, and, for example, whereinformation to be complemented as scheduling information by thecomplementation section is known, not the information of the signal orthe message in the upward direction from the radio terminal 4-2 but theinformation just described may be stored in advance in the storagesections 303 and 313.

Further, with the relay station of the present invention, also signalsother than a band request signal such as the BW Request Code (requestcode) described above or a power/timing adjustment signal such as theRanging Code (ranging code) described above can be intensively collectedby the intensive collection section, and as a result, effectiveutilization of a band can be achieved.

Further, the apparatus of the present invention can be fabricated by aperson skilled in the art based on the disclosure of the embodimentsdescribed above.

What is claimed is:
 1. A relay station which relays a signal to betransferred between a radio base station and a radio terminal, the relaystation comprising: a terminal side reception section adapted to receiveinformation of a signal and a message transmitted from the radioterminal; a decision section adapted to decide based on the informationreceived by said terminal side reception section whether or not anotification of the information relating to the signal and the messagereceived from the radio terminal is to be issued to the radio basestation; and a notification section adapted to issue the notification ofthe relating information to the radio base station when it is decided bysaid decision section that the notification of the information relatingto the signal and message received from the radio terminal is to beissued to the radio base station.
 2. The relay station as claimed inclaim 1, wherein said terminal side reception section receivesinformation of a signal and a message relating to a radio channel statebetween the relay station and the radio terminal transmitted from theradio terminal; said decision section decides, based on the informationrelating to the radio channel state between the relay station and theradio terminal received by said reception section, that a notificationof the relating information is to be issued to the radio base stationwhen a radio communication method used between the relay station and theradio terminal need be changed; and said notification section issues,when it is decided by said decision section that the radio communicationmethod need be changed, a notification of at least one of the radiochannel information and the radio communication method between the relaystation and the radio terminal as a notification of the relatinginformation to the radio base station.
 3. A radio communication systemcomprising a radio terminal, a radio base station for transmitting andreceiving a signal to and from the radio terminal, and a relay stationfor relaying a signal transferred between the radio terminal and theradio base station; the relay station comprising: a radio channel statereception section adapted to receive information of a signal and amessage relating to a radio channel state between the relay station andthe radio terminal from the radio terminal; a decision section adaptedto decide based on the information received by the channel statereception section whether or not a radio communication method to be usedbetween the relay station and the radio terminal need to be changed; anda notification section adapted to issue, when it is decided by thedecision section that the radio communication method needs to bechanged, a notification of at least one of radio channel information andthe radio communication method between the relay station and the radioterminal as relating information to the radio base station; the radiobase station comprising: a scheduling information production sectionadapted to change a radio communication method to be used between theradio base station and the radio terminal through the relay station andproduce scheduling information in communication wherein the radiocommunication method is changed based on the relating information issuedfrom the notification section; and a transmission section adapted totransmit the scheduling information produced by the schedulinginformation production section to the relay station.
 4. The radiocommunication system as claimed in claim 3, wherein the radiocommunication method which is a target of the change includes amodulation method, a coding method and a coding ratio as elementsthereof.